1. Field of the Invention
The present invention relates to diode pumped solid state lasers. More specifically, it relates to the production of high energy bursts from a solid state laser operated in a heat capacity limited regime.
2. Description of Related Art
Solid state laser technology is a very well developed field and numerous embodiments and modes of operation have been demonstrated. A more recent development has been the pumping of a solid state laser active medium with an array of diode lasers (diode pumping, for short). These diode pump packages have previously been developed to pump solid state lasers with good efficiency, but low average power.
Developments at Lawrence Livermore National Laboratory (LLNL), particularly with respect to diode cooler technology, have extended diode pumping to the regime of high average power operation. One of the key limitations in power performance levels in solid-state lasers is the waste heat deposited in the active medium during the lasing process. Removing this waste heat in steady state operation creates thermo-mechanical stresses which must be maintained at appropriate levels to avoid fracture of the lasing medium. In the case of slab geometries (both Brewstee slab as well as Zigzag slab), these critical tensile stresses are on the large flat faces which are not amenable to available strengthening approaches. This stress fracture limitation has limited the average powers available from solid state lasers to a level where a variety of military applications are out of reach if approached using this conventional steady-state technology.
U.S. Pat. No. 5,034,953 is directed to a laser device which achieves a uniform temperature distribution within a slab-shaped medium by reciprocating the slab-shaped laser medium relative to the excitation member. U.S. Pat. No. 5,022,043 is directed to a high power diode pumped solid state laser with an unstable resonator. This laser uses a bundled end of light transmitting fibers to provide a high powered pump. U.S. Pat. No. 4,952,586 discloses a high power diode pumped laser using a low power control beam pumped into a laser medium excited by laser diodes.
U.S. Pat. No. 4,951,294 is directed to a diode pumped mode-locked solid state laser. U.S. Pat. No. 5,077,750 discloses a high power laser that is a combination of multiple amplified beams. U.S. Pat. No. 5,077,751 is directed to a high output laser which optically couples multiple laser beams. U.S. Pat. No. 5,081,637 is directed to a high power laser which uses collimated multiple diode laser pumps.